The Immunology and Safety of Maternal RSV Vaccination (ABRYSVO), Infant Nirsevimab (BEYFORTUS) Immunization, or Both Products

NCT06551506 · Status: COMPLETED · Phase: PHASE4 · Type: INTERVENTIONAL · Enrollment: 181

Last updated 2026-05-11

No results posted yet for this study

Summary

Respiratory Syncytial Virus (RSV) is the leading cause of lower respiratory tract infections (LRTIs) in infants and young children. It is also a leading cause of mortality in children \<5 years of age worldwide. Until recently, no Food and Drug Administration (FDA)-approved vaccines were available to prevent RSV infection. The only prophylactic product for RSV prevention recommended for infants was the monoclonal antibody palivizumab, but administration was limited to those with extreme prematurity, chronic lung disease, or hemodynamically significant congenital heart disease. However, in 2023, the FDA approved two products designed to prevent RSV lower respiratory tract disease (LRTD) in all infants: an active RSV vaccine based on the prefusion F protein (RSVpreF, ABRYSVO, Pfizer) administered during pregnancy, and a passive, long-acting monoclonal antibody (nirsevimab-alip \[henceforth referred to as nirsevimab\], BEYFORTUS, AstraZeneca) administered to infants at birth or at the start of their first RSV season. Both products were evaluated in Phase 3 pivotal clinical trials and have high efficacy in preventing LRTD caused by RSV in infants. Although there is no established correlate of protection against RSV, antibodies have been associated with protection across multiple studies. The clinical development plan for the products did not include comprehensive evaluations of the magnitude and durability of the immune response, nor were the two products tested in a single trial. This study is a prospective, randomized, open-label Phase 4 study with the primary objective of evaluating the magnitude and durability of RSV-specific neutralizing antibodies in infants through 12 months of life following either maternal RSV vaccination, infant nirsevimab administration, or both products combined.

Conditions

  • Respiratory Syncytial Virus Infection

Interventions

BIOLOGICAL

Abrysvo

A maternal RSV vaccine based on the prefusion F protein administered during pregnancy

BIOLOGICAL

Beyfortus

A passive, long-acting monoclonal antibody to Respiratory syncytial virus (RSV) administered to infants

Sponsors & Collaborators

  • National Institute of Allergy and Infectious Diseases (NIAID)

    lead NIH

Study Design

Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Model
PARALLEL

Eligibility

Min Age
18 Years
Max Age
45 Years
Sex
FEMALE
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2024-09-19
Primary Completion
2026-05-05
Completion
2026-05-05

Countries

  • United States

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT06551506 on ClinicalTrials.gov